Prevalence of human infection with Toxoplasma gondii has been increasing in China due to the increasing number of cats. However, little is known of the epidemiology of T. gondii infection in different cancer patient groups. Thus, a case-control study of 900 cancer patients and 900 controls was conducted to detect anti-T. gondii antibodies by ELISA in China. Genomic DNA was extracted from the diseased tissues of 510 patients and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP. The prevalence of anti-T. gondii IgG in cancer patients (35.56%) was significantly higher than that in controls (17.44%). The highest T. gondii seroprevalence was detected in lung cancer patients (60.94%), followed by cervical cancer patients (50%), brain cancer patients (42.31%) and endometrial cancer patients (41.67%). Exposure with soil and consumption of raw/undercooked meat were significantly associated with T. gondii infection in cancer patients. Three T. gondii genotypes (ToxoDB#9, ToxoDB#10 and Type I variant) were identified. In conclusion, T gondii infection is a severe problem in cancer patients and it is imperative that improved integrated measures should be conducted to prevent and control T gondii infection in cancer patients.

Background: The prevalence of infection with Toxoplasma gondii (T. gondii) in humans has been increasing in China due to the growing number of cats in the country. Hand, foot and mouth disease (HFMD) is a serious public health issue in China and still one of the leading causes of child mortality. However, little is known about the epidemiology of T. gondii infection among HFMD patients.
Methods: A case-control study of 281 HFMD patients from the First People's Hospital of Pingdingshan in Pingdingshan city, Henan province, central China, and 222 controls from Pingdingshan city was conducted. Anti-T. gondii antibodies were serologically detected using the enzyme-linked immunosorbent assay.
Results: We found that the overall anti-T. gondii immunoglobulin G (IgG) antibody prevalence among HFMD patients was 12.46 %, which was significantly higher than that in clinically healthy children (1.80 %). The highest T. gondii seroprevalence was detected in critical cases (22.58 %), followed by severe cases (11.50 %), and the lowest was detected in mild cases (8.33 %).
Conclusion: The present study is the first survey of T. gondii seroprevalence among HFMD patients in China; 12.46 % were defined as seropositive. It is imperative that improved integrated measures are taken to prevent and control T. gondii infection among HFMD patients.

Congenital toxoplasmosis and toxoplasmic encephalitis can be associated with severe neuropsychiatric symptoms. However, which host cell processes are regulated and how Toxoplasma gondii affects these changes remain unclear. MicroRNAs (miRNAs) are small noncoding RNA sequences critical to neurodevelopment and adult neuronal processes by coordinating the activity of multiple genes within biological networks. We examined the expression of over 1000 miRNAs in human neuroepithelioma cells in response to infection with Toxoplasma. MiR-132, a cyclic AMP-responsive element binding (CREB)-regulated miRNA, was the only miRNA that was substantially upregulated by all three prototype Toxoplasma strains. The increased expression of miR-132 was also documented in mice following infection with Toxoplasma. To identify cellular pathways regulated by miR-132, we performed target prediction followed by pathway enrichment analysis in the transcriptome of Toxoplasma-infected mice. This led us to identify 20 genes and dopamine receptor signaling was their strongest associated pathway. We then examined myriad aspects of the dopamine pathway in the striatum of Toxoplasma-infected mice 5 days after infection. Here we report decreased expression of D1-like dopamine receptors (DRD1, DRD5), metabolizing enzyme (MAOA) and intracellular proteins associated with the transduction of dopamine-mediated signaling (DARPP-32 phosphorylation at Thr34 and Ser97). Increased concentrations of dopamine and its metabolites, serotonin (5-HT) and 5-hydroxyindoleacetic acid were documented by HPLC analysis; however, the metabolism of dopamine was decreased and 5-HT metabolism was unchanged. Our data show that miR-132 is upregulated following infection with Toxoplasma and is associated with changes in dopamine receptor signaling. Our findings provide a possible mechanism for how the parasite contributes to the neuropathology of infection

Parasitic infections may induce variable immunomodulatory effects and control of autoimmune disease. Toxoplasma gondii (T. gondii) is a ubiquitous intracellular protozoan that was recently associated with autoimmunity. This study was undertaken to investigate the seroprevalence and clinical correlation of anti-T. gondii antibodies in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We evaluated sera from European patients with RA (n = 125) and SLE (n = 164) for the prevalence of anti-T. gondii IgG antibodies (ATXAb), as well as other common infections such as Cytomegalovirus, Epstein-Barr, and Rubella virus. The rates of seropositivity were determined utilizing the LIAISON chemiluminescent immunoassays (DiaSorin, Italy). Our results showed a higher seroprevalence of ATXAb in RA patients, as compared with SLE patients [63 vs. 36 %, respectively (p = 0.01)]. The rates of seropositivity of IgG against other infectious agents were comparable between RA and SLE patients. ATXAb-seropositivity was associated with older age of RA patients, although it did not correlate with RA disease activity and other manifestations of the disease. In conclusion, our data suggest a possible link between exposure to T. gondii infection and RA.

The immunosuppression hypothesis suggests that the increased sex ratio in mice and women with latent toxoplasmosis, retarded embryonic growth in the early phases of pregnancy, prolonged pregnancy of Toxoplasma-infected women, and increased prevalence of toxoplasmosis in mothers of children with Down syndrome can be explained by the presumed immunosuppressive effects of latent toxoplasmosis. Here, we searched for indices of immunosuppression in mice experimentally infected with Toxoplasma gondii. Our results showed that mice in the early phase of latent infection exhibited temporarily increased production of interleukin (IL)-12 and decreased production of IL-10. In accordance with the immunosuppression hypothesis, the mice showed decreased production of IL-2 and nitric oxide and decreased proliferation reaction (synthesis of DNA) in the mixed lymphocyte culture in the early and also in the late phases of latent toxoplasmosis. Since about 30% of the world population are latently infected by T. gondii, the toxoplasmosis-associated immunosuppression might have serious public health consequences.

Previous studies have shown that maternal antibodies to Toxoplasma measured during pregnancy are associated with an increased risk of schizophrenia and other psychoses in adult offspring Recently. it has been recognized that different genotypes of Toxoplasma have distinct neuropathogenic potential. The objective of this study was to investigate whether parasite genotype is a contributing factor to disease risk. We have developed an enzyme-linked immunosorbent assay (ELISA) that use., polymorphic polypeptides specific to the three clonal parasite lineages and derived from three dense granule antigens. GRA5, GRA6 and GRA7. We used this assay to measure type-specific antibodies in the sera from 219 pregnant women whose children developed schizophrenia and affective psychotic illnesses in adult life, and 618 matched unaffected control mothers from three cohorts of the Collaborative Perinatal Project. We found that the offspring of mothers with a serological pattern consistent with Toxoplasma type I infection were at significantly increased risk for the development of psychoses as compared with the matched unaffected control mothers (odds ratio = 1.94, 95% confidence interval = 1.08-3.46; p = 0.03). The risk was particularly elevated for affective psychoses (OR = 5.24, 95% CI = 1.67-16 5; p = 0 005). In contrast, we did not find an association between maternal antibodies to other genotypes and risk of psychoses in the offspring These findings suggest in influence of the parasite genotype on increased risk of psychosis and provide further support for a substantive role of Toxoplasma in the etiology of psychosis. (C) 2009 Elsevier Masson SAS All rights reserved